cannot open "zfs": no such pool
cannot open "list": no such pool
You could get a new or spare boot drive and install Windows on that on the Dell server. Disconnect the DATA drives so you only have the new, Windows boot drive at first. I would do all Windows updates and install the Klennet software. Power down and reconnect the DATA drives and run the Klennet software to see what it reports it can find.
zpool status
zfs list
Those should be run in the TrueNAS Shell (GUI). You may have to use sudo before them.
Follow PMH directions in his reply below.
1 Like
I appreciate the tips and will put them into practice.
If youâre crazy like me, you can boot from a WinPE live USB.
I would be afraid that wouldnât work with Klennet. The only reason we would boot Windows
Iâm going to test this with a ZFS pool on a USB stick. The free version of Klennet should allow a scan without needing a license. Will report my results.
To be able to boot into a live Windows 11 environment from a USB or âVentoyâ stick is really useful.
1 Like
You need to enter that at a Linux command line as user root.
2 Likes
Just booted into WinPE from a Ventoy USB stick, and I was able to download, install, and run Klennet Recovery.[1] It detected my ZFS pool (which I made on a USB drive for testing purposes) and was able to scan it.
I canât go any further than that, since it requires a license to actually recover the files.
This is not to say that you shouldnât install Windows on a separate SSD. Itâs just good to know that itâs possible to boot into a live Windows 11 session from a USB stick.
Like a Linux live ISO, the âDownloadsâ folder is in RAM and nothing is saved, since this is a live session only. âŠď¸
1 Like
Are you crazy enough to extend the testing to UFS Explorer RAID Recovery? Iâve just heard about it. As a bonus, even the free version should then let you recover small files (< 768 kB)⌠to the non-persistent live session. 
Is the âUFSâ in the title just a name? You want me to try to recover from a ZFS pool or from a UFS file-system?
I can try to do that today.
I can start an off-topic thread for it, so we wonât take away from @Jucelio_Rosaâs troubleshooting.
It lists ZFS on the webpage for that software
1 Like
It worked. I recovered two test files, both under 768 KB. A PDF and DOCX.
It shows that WinPEâs Windows 11 environment can install and run this software, without needing a separate drive to install Windows from scratch. This is what I discovered with âKlennetâ too.
In this case though, âUFS Explorerâ is supported on Linux and FreeBSD, so a Windows environment isnât even needed.
1 Like
Thanks for confirming that there is now an alternative to Klennet Recovery for desperate cases. Of course, it is possible that one works better than the other on actual damaged pools.
In either case, recovery requires enough space to recover (i.e. at least one large enough HDD) and some boot media to install the recovery OS.
1 Like
Unfortunately, if the pool or file-system metadata is corrupt, meaningful recovery is almost moot for anything more complex than a stripe or mirror.
Here is a case example of what I mean. Youâll notice that Klennet is probably using heuristics and âsignaturesâ when it comes across 4KB thumbnails (or EXIF thumbnails), yet it cannot even recover larger files. Whatâs even sadder is that it cannot retrieve the original paths, file names, or modification dates.
The reason it âfindsâ images is because of the âsignatureâ for a JPEG image. From here, it loads sequential data for the start of the image, but then falls short. This is because the actual remaining data for the JPEG image is âsomewhere elseâ. The tool âPhotorecâ does the same thing for free, but without a fancy UI to review the results and choose what to recover.
Because Iâm very apprehensive, Iâm making a backup and will test your suggestions later.
How are you making that backup?
I think this is a production system and, hopefully, has real, validated backups. I think the user is worried about the recovery software process and not being able to bring system back.
I would expect the recovery software would be mounting the pools as read only but I have never used either of the packages mentioned.
Good afternoon. I removed the hard drive with TrueNAS, installed Windows on it, and installed the Wondershare Recoverit software, since I already had a license. I recovered some files. I couldnât scan all the partitions (due to lack of time), and I plan to return next Saturday. Some files were actually recovered, and others came back blank.
Why did you not try to import the pool, first? That has a chance of recovering all data âŚ
I am not questioning your general experience or troubleshooting skills, but if this is a business critical machine why does the customer bring in a guy who as he himself said has no experience with TrueNAS, needs to travel, is only available on Saturdays âŚ
This all reads a bit strange, donât you think?
They could have brought in someone local with TrueNAS and Linux/Unix command line experience within a day or two âŚ
EDIT: also ⌠hook up an IP KVM and let a TrueNAS specialist dial in. Easy peasy.
The issue is that no pool were found to be imported.